jump to navigation

The Obstacles to Increasing Human Speed August 29, 2008

Posted by Matt Brown in Human Enhancement, Speed.
Tags: , ,

I recently read an article that made the claim that with the help of technology it will be possible to make human beings faster than we ever thought possible, with 100m times under 5 seconds not out of the realm of possibility.  According to the article, ” Professor Peter Weyand, Southern Methodist University (Texas), known for his expertise in terrestrial locomotion and human and animal performance, told TOI that humans would soon have the ”ability to modify and greatly enhance muscle fibre strength.” This is crucial as it would actually reduce the difference between the muscle properties of humans and the world’s fastest animal, the cheetah, to almost zero.”

With all due respect, and I blame the article more than the Professor for leaving this out, but it’s not that simple.  Certainly increasing muscular strength is the first and arguably most important step to increasing speed but it’s not the only hurdle.  It may come as a surprise to some that our strongest and fastest athletes today don’t even use all of their potential strength when they compete.  If they could they would but their bodies won’t let them.  Due to what’s called autogenic inhibition, in most instances where we exert ourselves near our maximum, the body blocks our ability to utilize all our muscle fibers.  In other words, we are only able to use a percentage of our full strength.  The reason for this is simple.  We are not designed to withstand the forces that our bodies would produce if we could utilize our full strength.  In cases were people have been over to override autogenic inhibition, such as when a man lifts a boulder off of himself to save his own life or when a mother lifts a car off her child, people have been known to rupture muscles or even tear tendons right off the bone.  Clearly, simply increasing muscle strength is only part of the answer.

If you want to build a faster human, there are a few things you have to do.  The first is change the actual composition of the muscle.  If your going for pure speed then Type II b muscle fibers are ideal.  These produce the greatest amount of force due to, among other reasons, the fact that more fibers are connected to a single motor neuron than with Type II a or Type I fibers.  While it is possible to change a small amount (10% at most) of muscle fibers from one type to another through training, we currently have no method for changing the composition of an entire muscle.  Next comes strengthening the muscle itself, either through hypertrophy ( making the fibers bigger) or hyperplasia (making more muscle fibers.)  Both of these are possible and may only be a few years away due to treatments such as stem cells to build new muscle fibers and myostatin inhibition to increase there size.  In addition it is important to increase the strength of the tendons and bones as well, for reasons previously mentioned.  I currently know of no method for increasing the strength of tendons and bones other than the old fashion way of resistance training, which I doubt would be sufficient.  It may require increasing the density of bones or perhaps even changing their composition to stronger materials, but that is just speculation on my part.

If the challenges are overcome, all of the above will make humans faster, but if you really want to improve speed your going to have to do something drastic.  As mentioned elsewhere in the article,  ‘‘The fast four-legged runners or quadrupeds do seem to be advantaged versus bipeds in terms of the mechanics allowed by their anatomy. These mechanics help quadrupeds to get the most out of the muscles that they have in a way that bipedal runners probably cannot.” If you want to make humans the fastest animal on earth, we’re going to have to ditch the hands for another pair of feet.




1. Joshua - August 29, 2008

I’ve been thinking about this too after the Olympics.

I know how to increase the strength of tendons – take mysostatin. While blocking myostatin results in more muscle mass, it also results in stiffer but smaller and more brittle tendons. I believe this is due to myostatin playing a role in the growth of tendon fibroblasts, such that myostatin produces more collagen in the tendons (making them more elastic and resilient). See this paper by Chris Mendias. This will be a major issue for those athletes that wish to take myostatin inhibitors. Perhaps only with a targeted approach, allowing myostatin to reach the tendon fibroblasts but not the myocytes, will this result in a safe form of muscle enhancement.

As for bone, I don’t think there is a quick fix for strengthening bones without increasing brittleness. This is due to limitations of the hydroxyapatite ceramic that is used for vertebrate bones, I think. We might just have to move to an all-metal skeleton (if that every becomes possible).

As for the comment about bipedalism and running, I’d like to point out that ostriches can run at 75km/h with their two legs. That’s pretty fast (not as fast as a horse or cheetah though).

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: